C211D

DTC C211D: Abnormal IG1 power supply high voltage





CAUTION: If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, always diagnose the CAN bus lines.

OPERATION
AWD-ECU detects an IG1 power supply voltage abnormal increase, and if any abnormality occurs, it interrupts the system.

DTC SET CONDITIONS
If the following conditions are met when the system is activated, AWD-ECU gradually switches the control from AWD to FWD, flashes the AWD/LOCK indicators alternately, and sets the DTC No. C211D.

^ IG1 voltage: More than 17 V
^ Battery voltage: Less than 16 V

TROUBLESHOOTING HINTS

Current trouble
^ Malfunction of IG1 relay in ETACS-ECU
^ Damaged wiring harness and connectors
^ Short or open circuit between the battery and AWD-ECU
^ Malfunction of alternator or other power supply systems

Past trouble
^ Intermittent wiring harness or connector failure

NOTE: For diagnosis procedures, refer to "How to treat past trouble".

^ Intermittent malfunction of ETACS-ECU (malfunction of IG1 relay)
^ Malfunction of alternator or other power supply systems

DIAGNOSIS
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A

STEP 1. Scan tool MB991958 CAN bus diagnostics
Use scan tool MB991958 to diagnose the CAN bus lines.

Q:Is the check result normal?
YES: Go to Step 3.
NO: Repair the CAN bus line. On completion, go to Step 2.

STEP 2. Check whether the DTC is reset after repairing the CAN bus line.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3) Check if the DTC is set.

Q:Is the DTC No. C211D set?
YES: Go to Step 3.
NO: This diagnosis is complete.

STEP 3. Check the following connector:
Check the connectors below for improper engagement, terminal damage or terminal drawn in the connector case.

^ C-128 AWD-ECU connector
^ C-309, C-313 ETACS-ECU connector

Q:Are the connectors and terminals in good condition?
YES: Go to Step 4.
NO: Repair the connector(s) or terminal(s). Then go to Step 7.

STEP 4. Voltage measurement at the AWD-ECU connector
(1) Disconnect the C-128 AWD-ECU connector.
(2) Measure the voltage between the C-128 wiring harness side connector terminals No. 4 and No. 10.

OK: Battery voltage

Q:Is the check result normal?
YES: Go to Step 7.
NO: Go to Step 5.

STEP 5. Wiring harness check
Check the wiring harness between the C-128 AWD-ECU connector (terminal No. 4) and the C-309 ETACS-ECU connector (terminal No. 1) for damage or other problem.

Q:Is the wiring harness in good condition?
YES: Go to Step 6.
NO: Repair the wiring harness. Then go to Step 7.

STEP 6. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3) Check if the DTC is set.

Q:Is the DTC No. C211D set?
YES: Replace AWD-ECU. Then go to Step 7.
NO: The trouble can be an intermittent malfunction.

STEP 7. Check whether the DTC is reset.
(1) Erase the DTC.
(2) Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3) Check if the DTC is set.

Q:Is the DTC No. C211D set?
YES: Diagnose again from Step 1.
NO: This diagnosis is complete.